Sash balance



- A. H. KERSTING April 25, 1933.

` sAsH BALANCE Filed oct. 19, 1951 15 whereby 5 Fig. 4. l

Patented 'Api'. 25, 1933 l UNITED 4STA E. mSTING, I L05 ANGELES, CALIFORNIA.

SABHBALANUI l 'Anuman mea come: 1a. 1m.- serm m. seems.

My invention relates to a sash balance of the type wherein the tension of a spiral spring is utilized for counterbalancin the weight of the sash with which the ba ance is associated and the principal objects of my invention are, to generally im rove upon and simplify the construction o the existing forms of sprin sash balances, to provid'e simple and e `lent means for producing and maintaining a certain degree of frictional resistance between the drum on which the sash supporting cable winds and tlle housing of the sash balance and furt er,

the degree of frictional resistance thus produced may be adjusted for window sash of varyin weights.

, Y A further o ject of m provdea sash balance o ferred to, wherein the inner convolutions of the spiral spring are utilized in connection with other parts for producing the desired frictional engagement between the cable carrying drum and the housing of the sash balance. l

With the foregoing. and .other objects in view, my invention consists in certain novel features of construction and arrangement of parts that will hereinafter be more full`y de- 3 scribed and claimed and illustrated in the accompanying drawin in which:

Fi 1 is a front e evational view of a sash alance constructed in accordance with my invention and with a portion of the front plate broken away. o

Fi 2 is a, ve ical section taken approximate y on the line 2-2 of Fig.`1.

Fig. 3 is an enlarged horizontal section 4o tiaken approximately on the line 3-3 of invention is, to

Fig, 3 and showing a modified form of the sash balance.

Fig. 5 is .a detail section showing the connection between the outer end of the spiral spring and the peripheral wall of the drum on which the cable winds.

Fig. 6 is an elevational view looking in. the direction indicated by the arrow 6 in to provide simple and eilicient means p the character re- 1. ig; 4 is a horizontal section similar to Fig. 7 is a detail section showing the connection between the inner end of the spiral spring and the tubular shaft or axle that supports said spring. v

1g. 8 is a perspective view of the tubular shaft or axle that serves as a support for the spiral spring in the species disclosed 111 1, 2 and 3. ferring by numerals to the accompanying drawing which illustrates a practical embodiment of my invention, 10 desi ates the housing of the balance which is su stantially rectangular in form and stamped or ressed from suitable sheet metal.

A front wall of cover-plate 11 of sheet metal serves as a closure for the housing 10 and by means of screws or like fastening devices 12, the ends of the cover plate are secured to the housing `10 and to the stile S of the window frame.

Arranged in the upper and lower of the ousing are horizontally tubular members 13 that serve as sup orts or iixed axles for the spiral springs an for the drums that enclose said spiral springs and the rear end of each of these tubular members 13 is rovided with two or more 'rearwardly projecting ears 14 that extend through arcuate apertures that are fo in the rear wall'of housing 10 and the outer ends of said ears are riveted- 'down a inst the outer face of the rear wall of the ousplrtionsposed ling so as to rigidly secure the tubular member to said housing.

Formed integral with tubular member 13, is a forwardly projecting ear. 15 that extends through an aperture that is formed in the cover plate 11 and after the parts of the balance have been properly assembled Within the housing, the outer end of this ear 15 is riveted down the front end of the against the outer face of the cover plate as hereinafter more fully described.

vThe length 0f the r such that its forward end terminates avshort distance inwardly from the inner face of the cover plate 11. 4

Formedin the tubular member 13 is a longitudinally disposed slot 16 through which passes a hook 17, that is formed on tubular member 13 is the inner end of a spiral s ring 18 and the outer end of this spring 1s detachably secured in an suitable manner, preferably by means of a o'ok 19 to the peripheral portion of a cable carrying drum.

This`drum comprises a disc-like wall 20,

l provided at its center withV an opening for 4that is inclined or flared so that it gradually increases in diameter away from the wall 20. A Bange 23 is Vformed-between the outer edge of wal120 and the adjacent edge of the peripheral wall 22 and the opposite edge of said peripheral wall 22 terminates in an outwardly projecting flange 24. A exible member 25, vpreferably a metal cable, is secured to. and is adapted to wind upon the inclined peripheral wall 22 of the drum and the free 'end of this cable carries a hook 26 or like device that is connected to the window sash.

A bow spring 27 is arranged between the spring 18 and the rear wall 20 of the drum, the ends of which spring bear on the face ofthe wall 20 opposite the face that is in contact with the wall of housing 10 and formed in the center of this spring 27 is an l aperture 28 for the accommodation of tubular member 13. When properly positioned between the rear wall 20 of the drum and spring 18, the

intermediate portion of spring 27 engages the rear edges of the inner convolutions of said spring 18.

When the parts of the sash balance have ybeen properly assembled and with the ear on the lforward end of tubular member 13 projecting through the front wall 11, the projecting end of said ear is riveted down so that the portion of the cover late 11 adjacent'to the forward end of tu ular member 13 and the ear 15 bears directly against y the front edges of the inner convolutions of the spring v18 and, as this particular portion lof wall 11 is forced inwardly during the rivc ting operation, the engaged inner convolutions of spring 18 will press the central portlon of spring 27 toward the rear wall of the drum, thereby increasing the tension in spring l27, so kthat its ends will bear with considerable pressure against the rear wall of the drum and consequently cause said rear wall to bear with considerable friction '7 against the wall of housing 10.

Before being placed in service, the sash balance 1s tested by connecting the end of lthe cable to a suitableA tension `gauge and unreeling said cable and the operator or workman that assembles the sash balance produces the desiredv degree of friction between the cable carrying drum and the housing by regulating the amount or degree of rliveti'ng'that i's imparted to the ear 15.

In the modified construction illustrated inrear wall of housing 10 andas said screw isy tightened, the portion of the front wall 11,-

adjacent to the head of the screw bears against the front edges of the innermost convolutions of the spring 18'L and acts through said convolutions to press the'cenftral Yportion of the rear wall of drum 20a 'rearwardly and thereby increase the tension between the outer portion of said rear wall 20 and the real wall 10'.L of thehousing.

VThus it will be seen that I have provided a sash balance having a4 spiral spring for counterbalancing the weight of the sash with which the balance is associated and said balance being provided with simple and eicient means whereby the inner convolutions of the'spiralspring are utilized for producing and maintaining the'desired degree of frictional resistance between the spring and closing drum and the housing ofthe ba ance.v

in the size, form and construction of the various parts of my .improved sash balance may be made and substituted for those herein shown and described without departing from the spirit, of my invention, the scope of which is set forth in the appended claims.

v I claim as my invention: 1. In a sashbalance, a housing, a tubular axle secured to one of the walls of the housing a cabler carrying drum arranged for rotation upon said axle, a splral spring ar;

ranged within said drum, the inner end of which spring is connected to said axle, the outer end of which spring is connected to the peripheral portion of sald drum and means for causing the inner convolutions of saidy springA to 'exert constant pressure against said drum. A l y 2. In a sash balance, a'housing, a tubular Vaxle securedY to one of the walls of the hous-j housing.

It will be understood that minor changes 3. In a sash balance, a housing, an axle arranged within said housing and secured to one of the walls thereof, a cable carrying drum mounted for rotation on said axle, a

spiral spring within said drum, the outer end of which spring i's secured to the peripheral portion of said drum, the inner end. of which spring is secured to said axle and a bow spring arranged between said spiral spring and the wall of said drum.

4. In a sash balance, a housing, an axle arranged within said housing and secured to one of thewallsthereof, a cable carr ing drum mounted for rotation on said ax e, a spiral spring within said drum, the outer end of which s ring is secured to the peripheral rtion o said drum, the inner end of whic spring is secured to said axle, a bow spring arranged between said spiral spring and the wall of said drum and means for causing the inner convolutions of the spiral spring to engage with pressure against the' central portion of said bow spring.

5. In a sash balance, a housing, an axle arranged within said housing and secured to one of the walls thereof, a cable carrying drumnmounted for rotation on said axle, la spiralspring within 'said drum, the outer end of which `spring is secured to the peripheral portion of said drum, the inner end of which spring is secured to said axle and means for drawmg those portions of the walls ofv the housing adjacent to the ends of the axle toward each other and causing the innermost convolutions of the spring to exert pressure against said drum.

6. In a spring sash balance, a housing, a cable carrying drum arranged for rotation within said housing and frictionally engaging one of the walls thereof, a spiral spring arranged within said housing4 and adapted to yieldingly resist rotary motion of said drum in one direction and means cooperating with the walls of said housing and acting through the inner convolutions of said spiral spring for imparting ressure to that portion of the drum that rictonally engages the wall of said housing.

7. In a spring sash balance, a housing, a drum mounted orrotation. within said housing, a spiral spring arranged within said drum and adapted to yieldingly resist rotaryr motion thereof in one direction and adjustable means including the inner convolutions of said coil spring for exerting pressure on the wall of the drum and causin same to frictionally engage the wall of sai housing.

.In testimony whereof, I aiix my signature.

ALBERT H.- KERSTING. 

